The two-wire I2C-bus (Inter-Integrated Circuit bus) is a well-known serial data bus used for low-speed data communication and control between integrated circuits. The bi-directional I2C-bus uses a single serial clock line (SCL) and a single serial data line (SDA). The I2C-bus is capable of data transfers at a speed of 100 kbits/sec in the Standard Mode, of up to 400 kbits/sec in the Fast Mode, and of 3.4 Mbits/sec in the High Speed mode. Some basic properties of the I2C-bus are described in U.S. Pat. No. 4,689,740, incorporated herein by reference. The skilled person has ready access to an abundance of literature in the art addressing the configuration and usage of the I2C-bus.